function F = fun_example(x,k)
F=zeros(2,1)
F=[x*(1-cos(2.54/(y+7.92)))-y^2*(x^2/(0.96^2+y^2)*(1-cos(2.54/(x+7.92)));
-1*(y^2+0.96^2)+x^2+6.21^2-2*cos(2.54/(2*(2.54+7.92)))*sqrt(x^2*6.21^2*sin(2.54/(2*(2.54+7.92)))-0.96^2*y^2)];
